Hemocompatible MOF-decorated pollen hemoperfusion absorbents for rapid and highly efficient removal of protein-bound uremic toxins

The accumulation of protein-bound uremic toxins (PBUTs) in the blood may result in the development of uremia into advanced stages. However, traditional hemoperfusion absorbents for PBUT removal have the main drawbacks of non-specific adhesion of plasma proteins, lower PBUT adsorption efficiency and poor hemocompatibility. Here, we report a micro–nanostructural design to synthesize a novel hemocompatible hemoperfusion absorbent by combining nanoporous hollow microspheres and PBUT-absorbing nanoparticles. Natural pollen nanoporous hollow microspheres were used as a skeleton to accelerate PBUT adsorption, and the PBUT-absorbing NU-1000 nanoparticles were in situ grown and decorated on the pollen skeleton (PPNU) via the intermediation of a polydopamine layer. Moreover, heparin was modified on the PPNU (PPNUH) to offer excellent hemocompatibility without sacrificing the PBUT-adsorbing sites of NU-1000. PPNUH specifically adsorbed PBUTs and possessed a high maximum adsorption capacity for various PBUTs (282 mg g−1 for p-cresyl sulfate, 329 mg g−1 for indoxyl sulfate, and 188 mg g−1 for quinoline acid). Furthermore, the integration of nanoporous hollow microspheres and PBUT-absorbing nanoparticles permitted quick adsorption of 85% of the free PBUT within 10 s while removing 70% of albumin-bound PBUTs within the first 1 min in simulated hemoperfusion. The exquisite micro–nanostructure of PPNUH and heparin modification synergistically achieved the efficient, rapid, and safe removal of PUBTs, and the design strategy provided a guiding idea for the development of future multifunctional and portable hemoperfusion materials.